1. Field of the Invention
The present invention generally relates to procedures and equipment for performing resections and ablations, particularly of the endometrium to control uterine bleeding (menorrhagia). More particularly, this invention relates to a device and procedure for performing a partial ablation, e.g., of the endometrium, by which complications caused by total/global ablation or resection are minimized or avoided.
2. Description of the Related Art
Electrosurgical resection is a procedure in which damaged, diseased or enlarged tissue is removed with an electrocautery probe. An example is endometrial ablation, which is an electrosurgical alternative treatment to hysterectomy in women with menorrhagia (abnormal uterine bleeding). Another example of electrosurgical resection is transurethral resection of the prostate (TURP), in which prostate tissue is removed by means of an electrocautery probe (e.g., a cutting loop) that is passed through the urethra by means of a resectoscope.
In endometrial ablation, the entire endometrium is ablated to expose myometrium, hence the term total (global) endometrial ablation. Total ablation of the endometrium is currently performed by three methods: through a cystoscope or endoscope using a laser and/or laser fiber to deliver energy to the tissue; through a resectoscope using electrodes, such as the roller and cutting loop electrodes taught in U.S. Pat. Nos. 5,759,183 and 5,919,190 to VanDusseldorp in a procedure known as total rollerball endometrial ablation (TREA); and by the use of intrauterine endometrial ablation devices. Conventional ablation and resection procedures often entail the use of an electrode or laser that is inserted into a cavity (e.g., endometrial cavity) through a resectoscope or hysteroscope. The electrode or laser tip is then moved along the walls of the uterus in a pattern (such as in resection), delivering radio frequency (RF) or laser energy to the tissue. Depending on power and wave length combinations, this procedure totally resects and/or coagulates (ablates) both the anterior and posterior walls of the endometrial cavity. Other global endometrial ablation devices incorporate other technologies to heat or freeze the walls of the cavity (e.g., the endometrium), such that the wall tissue dies. Though some of these devices are placed through a resectoscope or hysteroscope, they are not necessarily in the form of a conventional xe2x80x9cresectoscopexe2x80x9d electrode.
Each of the above-noted modalities ablates, resects or freezes the entire intrauterine cavity, accounting for the term total or global ablation, which is represented in FIG. 1. It is believed that there are various unique long-term complications that can follow total endometrial ablation. After the endometrium is ablated (destroyed), myometrium is exposed. After the distention media is removed, the intrauterine walls collapse upon each other and may grow together, causing an intrauterine contracture which reduces the cavity into a narrow tubular structure often obstructing the corneal area. Endometrial tissue has a tendency to persist or regenerate in the corneal and intramural tubal areas, which can bleed causing symptomatic corneal hematometra (CH) or retrograde menstruation with resultant endometriosis. In patients who have had a tubal ligation, retrograde bleeding can cause a painful tubal distention known as post ablation tubal sterilization syndrome (PATSS). Central hematometra is generally caused by resecting/ablating too far into the upper cervical canal. Devices or procedures that totally or globally ablate the interior walls of the uterus increase this potential problem. Moreover, intrauterine contracture and scarring caused by total ablation may delay bleeding and the diagnosis of endometrial cancer. Nonetheless, conventional wisdom is that total endometrial ablation is required to treat menorrhagia.
The present invention provides a very controlled xe2x80x9cpartialxe2x80x9d ablation treatment, and a device for performing the partial ablation treatment. According to the invention, partial ablation of the endometrium avoids the development of adhesions and contracture, which are believed to occur following total (global) endometrial ablation procedures conventionally employed to treat menorrhagia. The device of this invention is able to perform a partial ablation in a single procedure, such as by providing controlled electrosurgical ablation of either the anterior or posterior endometrial wall, instead of both as previously done with prior art devices and procedures in accordance with conventional wisdom. The device and procedure of the invention are able to correct menorrhagia without causing intrauterine scarring, with the preferred result being hypomenorrhea or eumenorrhea, not amenorrhea.
Accordingly, the partial ablation treatment of this invention is contrary to the conventional wisdom that total ablation is required to treat menorrhagia.
The partial ablation device of the invention generally includes a support member, a first conductor member supported with the support member and reciprocable relative to the support member with one end of the first conductor member extending beyond the support member, at least one electrically nonconducting member preferably interconnecting the support member and the first conductor member, and at least one flexible conductor member supported with the support member and interconnected with the first conductor member. Retraction of the first conductor member relative to the support member moves the end of the first conductor member toward the support member, causing the nonconducting and conductor members to expand outward from the first conductor member in substantially opposite directions.
When performed with the device described above, the partial ablation procedure of this invention generally entails the steps of inserting the device within the intrauterine cavity of the human body, and then retracting the first conductor member relative to the support member to move the end of the first conductor member toward the support member, causing the nonconducting and conductor members to expand outward from the first conductor member in substantially opposite directions. A current is then caused to flow through the flexible conductor member(s) so as to ablate and/or coagulate one wall (partial) of the tissue of the intrauterine cavity.
From the above, one skilled in the art will realize that the partial ablation procedure of this invention is contrary to conventional wisdom that total endometrial ablation is required to treat menorrhagia. With the device of this invention, the partial ablation procedure is relatively quick and requires less expertise than that required to operate a conventional resectoscope for prior art total (global) ablation procedures. In one embodiment of the invention, the device is adapted for use in a doctor""s office or in a hospital or surgery center operating room, and has the advantage of direct vision for placement as well as observation of the ablation process. In another embodiment, the device is adapted to have a smaller diameter for use in a doctor""s office as a standalone self-contained device placed under ultrasound. With the above embodiments of the invention, the entire office visit may be reduced to an hour, with only ten to fifteen minutes being potentially necessary for the actual procedure. In still another embodiment, a larger device is adapted for use in a hospital or surgery center operating room, and can be placed under direction vision or through any standard resectoscope or hysteroscope. In addition to being adapted to perform the partial ablation procedure of this invention, an advantage of each embodiment of the device is the ability to be manufactured to allow for its disposal after the procedure.
Other objects and advantages of this invention will be better appreciated from the following detailed description.